You can
put this solution on YOUR website!(X) = .0031X*2 - .291X + 7.1, where X is the age of the driver ( 16 < X < 88)
Question: AT WHAT AGE IS THE ACCIDENT RATE THE LOWEST?
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You have a quadratic function with coefficients a,b and c.
The mimimum occurs at x=-b/2a
x = -(-0.291)/(2*0.0031)
x = 46.935 yrs. of age
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Cheers,
Stan H.